Tractor-frame suspension



E. E. WICKEHSHAM.'

TRACTOR'FRAME SUSPENSION.

APPLICATION FILED SEPT. 29, 1919. l y 1,4295473. PatentedSept. 19, 11.222.

2 SHEETS-snee? 1.

Inventar' A TTORNE YS E. E. WLCKERSHAM. TRACTOR FRAME SUSPENSION.

1922. 2 SHEETS-SHEET 2.

APPLICATION FILED SEPT-29.1919.

Patented Sept. 19,

ATTORNEYS FMA l [VL/ILV Patentedv Sept-19, 1922.

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:sm/1ER wICKERsHeM, or s'roC'KToN, CALIFORNIA,v AssIsNoR 'ro TH'E HoLT. MANU- FACTURING COMPANY, or sToCIi'roN, CALIFORNIA, A CORPORATION. or CALI- FORNIA.

'TRACTOR-FRAME SUSPENSION.

Application led .September 29, 1919. Serial No. 327,283.

To all inkom it may conceamf' Be it known that I, ELMER E. W'ICKER- si-IAM, a citizen of the Uriited States, resid- \l l .1* rame Suspensions, of which the following is a specification.

This invention relates to tractors of the chain track type, and more particularly tomeans for supporting the main frame upon the truck mechanisms.

In my prior application, Serial No. '314,-'.

205, filed July 30th 1919, I show and describe means for suspending the entire weight of the main frame at a single point upon each' of the truck'mech'anisms. The present invention contemplates a specifically different form of suspension of this general type wherein there "has been a simplification and improvement of the mechanism throughout.

Referring to the accompanying drawings:

Fig. 1 shows a plan view of a ltractor embodying my invention. y

Fig. 2 shows a side elevation ofthe same.

F ig. 3 shows apsectional view taken at the rear of the truck mechanisms.

Fig. 4 shows a detail sectional View of one of the stabilizing springs.

As herein shown,the tractor comprises a main fra-me 10 at gjach side ofv which is arranged. a self-laying track truck mechanismA comprising a truck frame 11 on which is journaled a series of rollers 12, at the forward end of which is journaled an idler sprocket wheel 13. An endless chain track 14 is carried at its forward run upon the idler wheel 13 and passes beneath the rollers 12 forming a track for'the latter. sprocket driving wheel]- 15 is journaled on thernain frame at the rear of the truck frame 11 and serves to Carry and drive the chain track 14. The entire weight of the main frame is supported at a singlepoint on each of thetruck framesll by means of a transverse supporting axle 16 fixed in hangers 17 on the main frame and having 'outwardly extending ends passing through bearings 18 formed on the truck frames. Each truck frame is free to rock about the axle 16 and the main frame is stabilized by meansof an upwardly extending bracket 19 formed on each yof the bearings 1S, said bracket 19 having an opening 2O in its point oneach of the truck frames 11.

upperend through which passes a thrust rod 21.

This thrust rod is guided at its forward end by a bracket 22 fixed to the main frame and at .its rearward endit is provided withv a cross-head 23v against which a pressure spring 23 abuts. This pressure spring 23 is carried in-a housing 24'fiXed-to the main frame.' A thrust washer 25, slidable on the rod'21, is inter'posed between the pressure spring and the upper end of the bracket 19. The rear end of the thrust rod 21 abuts against a series of balls 26, said balls being carried in a curved race 27, which race is secured to the rear end of the main framek and forms a connection between the thrust rods at opposite sides of the'main frame.

In the operation of the tractor it will be seen that the entire weight of the main frame is supported by the axle 16 at a single location of the axle 16 is `to the rear of the center of weight of the main frame and themain frame is Aprevented tilting downwardly at its forward end independent'of the truck frames by the pressure of the springs 23 against the upwardly Iextending brackets 19. Each truck frame is free to rock about The the axle 16, and, should one of these truckV mechanisms meet with an obstruction in the roadway, its forward end will move upwardly, causing the upwardly extendingv bracket 19 to rock rearwardly and exert a pressureon the adjacent spring 23. The pressure of this spring will force the connected thrust rod 21 rearwardly and the movement of this thrust rod 21r will act through the interposed balls 261150 compress the'opposite'spring 23. Thereby the compression of opposite springs 23 is equalized and a rising movement-of' the forward end of one' truck mechaiiism will impart a force to the opposite truck mechanism which will tend to move the forward end of the latter downwardly.

The mainframe is prevented from tilting downwardly at its rear end by reason of the fact that the center of weight of the main frame is forward ofthe support 16. In extreme cases, as in climbing 'a steep vrade where a` re )onderance of weight g 3 might possibly be. threatened upon the rear end, the standard or bracket 19 will prevent any radical downward movement of the rear end of the main frame. Thus itwill be seenl that the driving sprocket Wheel 15 is not a load-supporting member and, so tar as the suspension of the main frame is concerned, it might be -removed entirely.

Having thus described my what l claim and desire toI secure by Letters Patent is:

Litri a' vehicle, a main frame, a chain track truck mechanism at each side thereof mounted for rocking movement 1n a verticalplane and equalizing connections between the main frame and opposite truck mechanisms comprising a ball race fixed upon the main frame, a series of balls in said race extending from one Side to the other of the main frame and brackets on each truck mechanism co-operating withtheballs in said race to cause opposite and equal movements of the truck mechanisms.

2. ln a Vehic1e,.a main rameVa chain track truck mechanism at each side thereof, an axle on the main frame at the rear of the center of. Weight thereof, a bearing for each end of the axle on the opposite truck mechanisms, an upwardly extending bracket formed on each of the bearings, a spring pressing against each of the brackets at the invention,

upper ends of the latter and connected with the main frainefor stabilizing the latter, Aand a connection between opposite springs to equalize the pressure of the latter.

3. In a vehicle, a main lframe, a chain track truck mechanism at each side thereof, an axle on the main frame at the rear of the center of Weight thereof, a bearing for each end of the axle on the opposite truck mechanisms, an upwardly extending bracket formed on each of the bearings, a spring pressing against each of the brackets at the upper endsof the latter and connected with the main frame for stabilizing the glatter, a connection between opposite springs to equalize thc pressure of the latter, said connection comprising a series of balls arranged between the opposite springs and a race for said balls fixed to the main frame.

ln testimony whereof l.l1ave'liereunto set my hand in the presence of two subscribing AWitnesses.

ELMER XVlCKERSHAM.'

Witnesses Vf. W. HEALEY, J. H. HERRING. 

